Driving towards Conwy Castle in North Wales it’s hard to imagine hundreds of workmen crawling over it like ants during the frenzied four years it took to build the mammoth towers and walls.

Conwy Castle, sitting powerfully beside the river from which it gets its name, is remarkable for one thing. King Edward I who employed his own builders to raise the walls built it over a frantic four-year period. It was a new castle, and is a testament to the quality of construction reflecting medieval building skills at their very best.

King Edward raised the castle after a destructive war, which threw him into many building projects designed to protect his borders. And the best way to do that in the late 13th century was to build a castle, and he didn’t just build Conwy, at around the same time he had his own kings workmen constructing Aberystwyth, Flint, Rhuddlan, Caernarfon, Harlech and Beaumaris castles! Some projects came to a halt due to a lack of money. Recession and a shortfall in tax revenues are not unique to the 21st century.

The castle is impressive because of its eight high towers linked by high, strong curtain walls. Taking a bird’s eye view you can see that it is in fact two castles divided by a middle gate with its own drawbridge. If one end was lost to the enemy defending soldiers could take refuge in the second half and continue fighting. Mind you attacking armies would have been hard pressed to initially get to the castle walls for the town was defended by 21 towers and three twin towered gates linking a lofty stone defendable wall.

Today the castle is listed as a World Heritage site and visitors would be impressed to know that some documents related to the castle’s construction still exist to this day. We know from the records that the two key players were James of St George, mason and engineer, who is often described as ‘master of the king’s works’ and Sir John de Bonvillars, who seems to have had overall authority.

Men from many nations had a hand in building the castle with engineers, masons and craftsmen from Italy, Switzerland, and France adding their skills and knowledge. Working together they built the castle with amazing speed initially spending £5,800, reckoned to be around 18 million in today’s money, up to the end of 1284 constructing the defensible towers and outer walls. By the time the castle was complete the equivalent of £45-million had flowed from Kind Edwards coffers to pay for men and materials.

The massive castle, its tall towers and walls still standing strong, is now an echoing shell with inner walls that clearly mark the Royal apartments, storerooms, banqueting hall and soldier’s accommodation. Looking up you ask yourself how did the builders and masons, during major construction periods around 1,500 craftsmen and labourers worked on the castle, get materials up to such dizzy heights?

They got round the engineering problem by building spiral ramps up from the ground, called the Savoyard technique, around the towers so that masons, carpenters and labourers could work ever higher. Today the towers and walls are bare stone, in medieval times they would have had a coat of white lime rendering on them, and some can still be seen around the castle, and especially around the entrance.

On-going repairs to the structure meant that skilled craftsmen were part of the retained castle staff, which would include the constable, who paid the soldiers, the garrison, including crossbowmen, stonemason, blacksmith, armourer and carpenter along with bakers, cooks and servants, who presumably came in from the town. Records show that in 1343 the roof of the bake house, brew house and kitchen were in a ruinous state and that it cost £60 to repair. Did conservation companies exist in the time of Edward I or were local tradesmen hired as required?

Conwy Castle is mainly built from local dark blue grey sandstone to reduce costs, although the towers are constructed from larger better quality dressed sandstone. All the wall infills and non-loadbearing thinner walls are local stone. Masons couldn’t work the local stones if they wanted to do decorative work, especially around the grander fireplaces, door and window frames or create intricate carved stonework, because the local stone was too soft, so harder stone had to be shipped in by sea from quarries around the Chester area.

Ironically the building could be said to have turned full circle as far as the actual care of the building is concerned. Originally designed and built by Edwards own ‘king’s works’ the Ministry of Works took over its restoration and repair programme in 1953. Then in 2007 Cadw, the Welsh Assembly’s historic environment service got the job of looking after this very special World Heritage site. You can only imagine that King Edward I would be pleased after building the castle in such haste and at such high cost?